Is the laboratory growth of Pacific oyster spat, Crassostrea gigas, exposed to varying salinities, predictive of their growth in the estuary?

Graduation date: 2000Results of this study suggest that laboratory growth of full-sib families of five\ud month old Pacific oyster spat can be predictive of growth to market size at different\ud grow-out sites. Seven to ten millimeter spat were selected from each of fifteen full-sib\ud families and commercially available polyploids. Each family was split into two\ud groups and exposed to either variable salinity (V.S., 3-30 ppt) or constant salinity\ud (C.S., 30 ppt) laboratory conditions for five months, then planted at either an upriver\ud or downriver subtidal site in the Yaquina estuary, Oregon. After six months of\ud growth in the estuary, the rankings of the families based on average individual\ud weights, specific growth rates (SGR), survival and yields were compared between\ud laboratory and estuary sites.\ud There was a significant effect of family, laboratory treatment and site upon\ud final individual live weights of oysters in the estuary (P=0.0001). The rankings of\ud families based on average individual laboratory weights were correlated with\ud average individual estuary weights at the downriver site (C.S. oysters, P=0.010,\ud V.S. oysters, P=0.005). Tetraploid oysters grew to heavier final estuary weights\ud than either triploids or diploids, with individual C.S. tetraploids averaging 79.4 g live\ud weight by fifteen months of age. Laboratory family rankings based on SGRs were\ud negatively correlated with estuary rankings of family SGRs for all treatments (P